mirror of
https://github.com/MoleskiCoder/EightBit.git
synced 2024-07-10 19:29:00 +00:00
388 lines
9.0 KiB
C++
388 lines
9.0 KiB
C++
#pragma once
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#include <cstdint>
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#include "IntelProcessor.h"
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#include "InputOutput.h"
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#include "Signal.h"
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namespace EightBit {
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class Z80 : public IntelProcessor {
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public:
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struct refresh_t {
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bool high : 1;
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uint8_t variable : 7;
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refresh_t(uint8_t value)
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: high((value & Bit7) != 0),
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variable(value & Mask7)
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{ }
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operator uint8_t() const {
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return (high << 7) | variable;
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}
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refresh_t& operator++() {
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++variable;
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return *this;
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}
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};
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struct opcode_decoded_t {
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int x;
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int y;
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int z;
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int p;
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int q;
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opcode_decoded_t() {
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x = y = z = p = q = 0;
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}
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opcode_decoded_t(uint8_t opcode) {
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x = (opcode & 0b11000000) >> 6; // 0 - 3
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y = (opcode & 0b00111000) >> 3; // 0 - 7
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z = (opcode & 0b00000111); // 0 - 7
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p = (y & 0b110) >> 1; // 0 - 3
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q = (y & 1); // 0 - 1
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}
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};
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enum StatusBits {
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SF = Bit7,
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ZF = Bit6,
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YF = Bit5,
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HC = Bit4,
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XF = Bit3,
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PF = Bit2,
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VF = Bit2,
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NF = Bit1,
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CF = Bit0,
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};
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Z80(Memory& memory, InputOutput& ports);
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Signal<Z80> ExecutingInstruction;
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void di();
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void ei();
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int interruptMaskable(uint8_t value) { return interrupt(true, value); }
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int interruptMaskable() { return interruptMaskable(0); }
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int interruptNonMaskable() { return interrupt(false, 0); }
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int interrupt(bool maskable, uint8_t value);
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int execute(uint8_t opcode);
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int step();
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// Mutable access to processor!!
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virtual register16_t& AF() override {
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return m_accumulatorFlags[m_accumulatorFlagsSet];
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}
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virtual register16_t& BC() override {
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return m_registers[m_registerSet][BC_IDX];
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}
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virtual register16_t& DE() override {
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return m_registers[m_registerSet][DE_IDX];
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}
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virtual register16_t& HL() override {
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return m_registers[m_registerSet][HL_IDX];
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}
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register16_t& IX() { return m_ix; }
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uint8_t& IXH() { return IX().high; }
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uint8_t& IXL() { return IX().low; }
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register16_t& IY() { return m_iy; }
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uint8_t& IYH() { return IY().high; }
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uint8_t& IYL() { return IY().low; }
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refresh_t& REFRESH() { return m_refresh; }
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uint8_t& IV() { return iv; }
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int& IM() { return m_interruptMode; }
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bool& IFF1() { return m_iff1; }
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bool& IFF2() { return m_iff2; }
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bool& M1() { return m1; }
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void exx() {
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m_registerSet ^= 1;
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}
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void exxAF() {
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m_accumulatorFlagsSet = !m_accumulatorFlagsSet;
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}
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virtual void reset();
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virtual void initialise();
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protected:
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InputOutput& m_ports;
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enum { BC_IDX, DE_IDX, HL_IDX };
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std::array<std::array<register16_t, 3>, 2> m_registers;
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int m_registerSet;
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std::array<register16_t, 2> m_accumulatorFlags;
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int m_accumulatorFlagsSet;
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register16_t m_ix;
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register16_t m_iy;
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refresh_t m_refresh;
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uint8_t iv;
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int m_interruptMode;
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bool m_iff1;
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bool m_iff2;
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bool m1;
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bool m_prefixCB;
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bool m_prefixDD;
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bool m_prefixED;
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bool m_prefixFD;
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int8_t m_displacement;
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bool m_displaced;
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std::array<opcode_decoded_t, 0x100> m_decodedOpcodes;
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int fetchExecute() {
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M1() = true;
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return execute(fetchByte());
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}
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uint8_t& DISPLACED() {
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m_memory.ADDRESS().word = MEMPTR().word = (m_prefixDD ? IX() : IY()).word + m_displacement;
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return m_memory.reference();
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}
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uint8_t& R(int r, uint8_t& a) {
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switch (r) {
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case 0:
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return B();
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case 1:
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return C();
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case 2:
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return D();
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case 3:
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return E();
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case 4:
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return HL2().high;
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case 5:
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return HL2().low;
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case 6:
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if (!m_displaced) {
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m_memory.ADDRESS() = HL();
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return m_memory.reference();
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}
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m_displacement = fetchByte();
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return DISPLACED();
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case 7:
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return a;
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default:
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__assume(0);
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}
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throw std::logic_error("Unhandled registry mechanism");
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}
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uint8_t& R2(int r, uint8_t& a) {
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switch (r) {
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case 0:
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return B();
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case 1:
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return C();
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case 2:
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return D();
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case 3:
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return E();
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case 4:
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return H();
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case 5:
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return L();
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case 6:
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m_memory.ADDRESS() = HL();
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return m_memory.reference();
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case 7:
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return a;
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default:
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__assume(0);
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}
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throw std::logic_error("Unhandled registry mechanism");
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}
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register16_t& RP(int rp) {
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switch (rp) {
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case 3:
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return SP();
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case HL_IDX:
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return HL2();
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default:
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return m_registers[m_registerSet][rp];
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}
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}
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register16_t& HL2() {
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if (!m_displaced)
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return HL();
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if (m_prefixDD)
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return IX();
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// Must be FD prefix
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return IY();
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}
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register16_t& RP2(int rp) {
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switch (rp) {
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case 3:
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return AF();
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case HL_IDX:
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return HL2();
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default:
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return m_registers[m_registerSet][rp];
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}
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}
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void addViaMemptr(uint8_t& f, register16_t& hl, register16_t operand) {
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MEMPTR().word = hl.word + 1;
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add(f, hl, operand);
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}
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void sbcViaMemptr(uint8_t& f, register16_t& hl, register16_t operand) {
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MEMPTR().word = hl.word + 1;
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sbc(f, hl, operand);
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}
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void adcViaMemptr(uint8_t& f, register16_t& hl, register16_t operand) {
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MEMPTR().word = hl.word + 1;
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adc(f, hl, operand);
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}
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static void adjustHalfCarryAdd(uint8_t& f, uint8_t before, uint8_t value, int calculation) {
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setFlag(f, HC, calculateHalfCarryAdd(before, value, calculation));
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}
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static void adjustHalfCarrySub(uint8_t& f, uint8_t before, uint8_t value, int calculation) {
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setFlag(f, HC, calculateHalfCarrySub(before, value, calculation));
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}
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static void adjustOverflowAdd(uint8_t& f, uint8_t before, uint8_t value, uint8_t calculation) {
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adjustOverflowAdd(f, before & SF, value & SF, calculation & SF);
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}
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static void adjustOverflowAdd(uint8_t& f, int beforeNegative, int valueNegative, int afterNegative) {
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auto overflow = (beforeNegative == valueNegative) && (beforeNegative != afterNegative);
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setFlag(f, VF, overflow);
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}
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static void adjustOverflowSub(uint8_t& f, uint8_t before, uint8_t value, uint8_t calculation) {
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adjustOverflowSub(f, before & SF, value & SF, calculation & SF);
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}
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static void adjustOverflowSub(uint8_t& f, int beforeNegative, int valueNegative, int afterNegative) {
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auto overflow = (beforeNegative != valueNegative) && (beforeNegative != afterNegative);
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setFlag(f, VF, overflow);
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}
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static void subtract(uint8_t& f, uint8_t& operand, uint8_t value, int carry = 0);
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void executeCB(int x, int y, int z);
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void executeED(int x, int y, int z, int p, int q);
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void executeOther(int x, int y, int z, int p, int q);
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static void postIncrement(uint8_t& f, uint8_t value);
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static void postDecrement(uint8_t& f, uint8_t value);
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void retn();
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void reti();
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bool jrConditionalFlag(uint8_t& f, int flag);
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bool returnConditionalFlag(uint8_t& f, int flag);
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bool jumpConditionalFlag(uint8_t& f, int flag);
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bool callConditionalFlag(uint8_t& f, int flag);
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static void sbc(uint8_t& f, register16_t& operand, register16_t value);
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static void adc(uint8_t& f, register16_t& operand, register16_t value);
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static void add(uint8_t& f, register16_t& operand, register16_t value);
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static void add(uint8_t& f, uint8_t& operand, uint8_t value, int carry = 0);
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static void adc(uint8_t& f, uint8_t& operand, uint8_t value);
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static void sub(uint8_t& f, uint8_t& operand, uint8_t value, int carry = 0);
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static void sbc(uint8_t& f, uint8_t& operand, uint8_t value);
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static void andr(uint8_t& f, uint8_t& operand, uint8_t value);
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static void xorr(uint8_t& f, uint8_t& operand, uint8_t value);
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static void orr(uint8_t& f, uint8_t& operand, uint8_t value);
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static void compare(uint8_t& f, uint8_t check, uint8_t value);
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static uint8_t& rlc(uint8_t& f, uint8_t& operand);
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static uint8_t& rrc(uint8_t& f, uint8_t& operand);
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static uint8_t& rl(uint8_t& f, uint8_t& operand);
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static uint8_t& rr(uint8_t& f, uint8_t& operand);
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static uint8_t& sla(uint8_t& f, uint8_t& operand);
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static uint8_t& sra(uint8_t& f, uint8_t& operand);
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static uint8_t& sll(uint8_t& f, uint8_t& operand);
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static uint8_t& srl(uint8_t& f, uint8_t& operand);
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static uint8_t& bit(uint8_t& f, int n, uint8_t& operand);
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static uint8_t& res(int n, uint8_t& operand);
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static uint8_t& set(int nit, uint8_t& operand);
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static void daa(uint8_t& a, uint8_t& f);
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static void scf(uint8_t a, uint8_t& f);
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static void ccf(uint8_t a, uint8_t& f);
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static void cpl(uint8_t& a, uint8_t& f);
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void xhtl(register16_t& operand);
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void blockCompare(uint8_t a, uint8_t& f);
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void cpi(uint8_t a, uint8_t& f);
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bool cpir(uint8_t a, uint8_t& f);
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void cpd(uint8_t a, uint8_t& f);
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bool cpdr(uint8_t a, uint8_t& f);
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void blockLoad(uint8_t a, uint8_t& f, register16_t source, register16_t destination);
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void ldi(uint8_t a, uint8_t& f);
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bool ldir(uint8_t a, uint8_t& f);
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void ldd(uint8_t a, uint8_t& f);
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bool lddr(uint8_t a, uint8_t& f);
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void ini(uint8_t& f);
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bool inir(uint8_t& f);
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void ind(uint8_t& f);
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bool indr(uint8_t& f);
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void blockOut(uint8_t& f);
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void outi(uint8_t& f);
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bool otir(uint8_t& f);
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void outd(uint8_t& f);
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bool otdr(uint8_t& f);
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static void neg(uint8_t& a, uint8_t& f);
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void rrd(uint8_t& a, uint8_t& f);
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void rld(uint8_t& a, uint8_t& f);
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void writePort(uint8_t port, uint8_t a);
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void writePort();
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void readPort(uint8_t port, uint8_t& a);
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void readPort();
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};
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} |